On several occasions in May, the U.S. had said it was likely that the meeting would be delayed, but the biggest hurdle was when the USA had called off the summit.
But the veteran diplomat, who was briefly considered for a post as Trump's ambassador to South Korea, warns the administration will face the same challenges and trade-offs in North Korea that its predecessors did.
Trump will attempt to secure a deal for full denuclearization of the Korean peninsula with Kim.
Secretary of State Mike Pompeo, who's met twice with Kim in preparation for the summit, said he and other advisers have been briefing Trump on a near-daily basis.
North Koreans were told two weeks ago that a summit between Kim and Trump would take place, but not when or where it would happen. "We are good for our word, we are meticulous, we pay attention to details - every smallest detail".
Mr Trump's first year in office was marked by bitter exchanges with Mr Kim as North Korea conducted several ballistic missile tests in defiance of worldwide warnings.
The cover of this week's edition of The Economis.
So how should Trump communicate with Kim? In this week's edition of the magazine, The Economist depicts Trump swinging on a wrecking ball-Miley Cyrus-style-and in its report warns that Trump's strategy may work in favour of his "America First" policy but risks a lonely America in the long run.
Image Kim Yo Jong also enjoyed a walkabout in Singapore
The Republic is no stranger to hosting historic summits. But he rightly points out that Trump "appears more interested in achieving a deal with North Korea than he is in maintaining peace with some of our oldest allies".
Trump on Monday morning was upbeat: "Great to be in Singapore, excitement is in the air!"
Offering a preview to reporters, Pompeo said it could provide "an unprecedented opportunity to change the trajectory of our relationship and bring peace and prosperity" to North Korea. But a series of diplomatic overtures involving North Korea, South Korea and the United States reduced tensions and led Trump in March to quickly accept Kim's invitation to meet.
However, Mr Lee warned that the tense situation in the Korean peninsular has been ongoing for up to 70 years, and one "cannot wipe that all away in one meeting". -North Korea summit in Singapore. Others complained about the jams in downtown Singapore.
Mr Kim and Mr Trump arrived in Singapore on Sunday for what will be the first-ever summit, set to held on Tuesday (June 12), between a leader of North Korea and a sitting U.S. president.
China and South Korea would have to sign off on any legal treaty. "I'm unconcerned about our capacity to continue to do what we need to do".
But analysts who closely watch North Korea believe it is unlikely Kim would have come to Singapore without being confident of the arsenal's security - and the ability to order its use.
Officials from the two sides held last-minute talks aimed at laying the groundwork for a meeting that was nearly unthinkable just months ago when the two leaders were exchanging insults and threats + that raised fears of war.
Plainclothes police and the explosives and ordnance disposal unit of the Singapore Army were seen working to prepare for a high-security event.More news: Afghan Taliban calls for ceasefire during Eid
More news: Yahoo Messenger Is Shutting Down After 20 Years
More news: Yoel Romero Misses Weight And Won’t Fight For Championship At UFC225